外源钙对低温胁迫下梨生理特性的影响

Effect of Exogenous Calcium on Physiological Characteristics of Pear under Low Temperature Stress

以玉露香梨为试材,分别设置CK(不喷钙)、T1(14 mmol/L CaCl_(2))、T2(21 mmol/L CaCl_(2))、T3(28 mmol/L CaCl_(2))、T4(14 mmol/L Ca(NO_(3))_(2))、T5(21 mmol/L Ca(NO_(3))_(2))、T6(28 mmol/L Ca(NO_(3))_(2))共7个处理,采用人工气候室在-2℃条件下研究外源钙调控梨花器官、叶片抗寒指标(MDA、SOD、POD、CAT)和光合指标(Pn、Tr、Ci、Gs)等生理指标对低温胁迫的响应,并用隶属函数法进行梨花器官抗寒性及梨叶片生理特性综合评价。结果表明,生理特性指标变异系数存在差异,SOD、POD、Gs生理指标更容易被人为调控;相关性分析可知,POD活性、CAT活性、Gs互呈显著正相关关系,Pn、Tr、Ci互呈显著正相关关系,POD活性、Pn、Gs、Tr互呈显著正相关关系,表明外源钙可通过调控光合性能促进植株抗寒能力的提升;通过隶属函数法分析表明,在梨花期喷施21 mmol/L Ca(NO_(3))_(2)以及在梨果实膨大期喷施21 mmol/L CaCl_(2),可显著抑制MDA的生成,分别使MDA减少32.7%、19.1%,可提升抗氧化相关酶的活性,分别使SOD提升41.1%、59.5%,使POD提升322%、122%,使CAT提升15.1%、46.1%,还可提高光合性能指标,使梨叶片净光合速率提高29.2%、蒸腾速率提高32.7%、气孔导度提高71.4%,进而提升梨产量及品质。

In this paper,Yuluxiang pear was taken as material tested,seven treatments including control(without calcium injection),T1(14 mmol/L CaCl_(2)),T2(21 mmol/L CaCl_(2)),T3(28 mmol/L CaCl_(2)),T4(14 mmol/L Ca(NO_(3))_(2)),T5(21 mmol/L Ca(NO_(3))_(2)),T6(28 mmol/L Ca(NO_(3))_(2))were set.Responses of physiological indexes such as flower organs,leaf cold resistance(MDA,SOD,POD,CAT)and photosynthetic indexes(Pn,Tr,Ci,Gs)regulated by exogenous calcium to low temperature stress were studied in an artificial climate chamber at-2℃,and the cold resistance of pear flower organs and the physiological characteristics of pear leaves were evaluated by membership function method.The results showed that there were differences in the coefficient of variation of physiological characteristic indexes,and the physiological indexes of SOD,POD and Gs were easier to be artificially controlled.By correlation study,POD activity,CAT activity and Gs showed a significant positive correlation with each other,Pn,Tr and Ci showed a significant positive correlation with each other,and POD activity,Pn,Gs and Tr showed a significant positive correlation with each other,indicating that exogenous calcium could promote improvement of plant cold resistance by regulating photosynthetic performance.The membership function analysis showed that spraying 21 mmol/L Ca(NO_(3))_(2)at flowering stage and21 mmol/L CaCl_(2)at fruit expansion stage could significantly inhibit production of MDA(32.7%and 19.1%),increase activities of antioxidant related enzymes such as SOD(41.1%,59.5%),POD(322%,122%),CAT(15.1%,46.1%),and increase the photosynthetic performance indexes such as net photosynthetic rate(29.2%),transpiration rate(32.7%)and stomatal conductance(71.4%)of pear leaves,so as to improve the yield and quality of pear.